package com.lee.utils;

import java.io.File;
import java.io.IOException;

import org.apache.shiro.crypto.hash.Md5Hash;
import org.apache.tomcat.util.http.fileupload.FileUploadBase.FileSizeLimitExceededException;
import org.springframework.web.multipart.MultipartFile;

import com.lee.config.LeeConfig;

/**
 * 文件上传工具类
 * 
 * @author LiPengFei
 *
 */
public class FileUploadUtils {

	// 默认大小 50M
	public static long defaultMaxSize = LeeConfig.getDefaultMaxSize();

	// 默认上传的地址
	private static String defaultBaseDir = LeeConfig.getProfile();

	// 默认的文件名最大长度
	public static final int DEFAULT_FILE_NAME_LENGTH = 200;

	// 默认文件类型jpg
	public static final String IMAGE_JPG_EXTENSION = ".jpg";

	private static int counter = 0;

	public static void setDefaultBaseDir(String defaultBaseDir) {
		FileUploadUtils.defaultBaseDir = defaultBaseDir;
	}

	public static String getDefaultBaseDir() {
		return defaultBaseDir;
	}

	/**
	 * 以默认配置进行文件上传
	 *
	 * @param file
	 *            上传的文件
	 * @return 文件名称
	 * @throws Exception
	 */
	public static final String upload(MultipartFile file) throws IOException {
		try {
			return upload(getDefaultBaseDir(), file, FileUploadUtils.IMAGE_JPG_EXTENSION);
		} catch (Exception e) {
			throw new IOException(e);
		}
	}

	/**
	 * 根据文件路径上传
	 *
	 * @param baseDir
	 *            相对应用的基目录
	 * @param file
	 *            上传的文件
	 * @return 文件名称
	 * @throws IOException
	 */
	public static final String upload(String baseDir, MultipartFile file) throws IOException {
		try {
			return upload(baseDir, file, FileUploadUtils.IMAGE_JPG_EXTENSION);
		} catch (Exception e) {
			throw new IOException(e);
		}
	}

	/**
	 * 文件上传
	 *
	 * @param baseDir
	 *            相对应用的基目录
	 * @param file
	 *            上传的文件
	 * @param needDatePathAndRandomName
	 *            是否需要日期目录和随机文件名前缀
	 * @param extension
	 *            上传文件类型
	 * @return 返回上传成功的文件名
	 * @throws FileSizeLimitExceededException
	 *             如果超出最大大小
	 * @throws FileNameLengthLimitExceededException
	 *             文件名太长
	 * @throws IOException
	 *             比如读写文件出错时
	 */
	public static final String upload(String baseDir, MultipartFile file, String extension)
			throws FileSizeLimitExceededException, IOException {

		assertAllowed(file);

		String fileName = encodingFilename(file.getOriginalFilename(), extension);

		File desc = getAbsoluteFile(baseDir, baseDir + fileName);
		file.transferTo(desc);
		return fileName;
	}

	private static final File getAbsoluteFile(String uploadDir, String filename) throws IOException {
		File desc = new File(File.separator + filename);

		if (!desc.getParentFile().exists()) {
			desc.getParentFile().mkdirs();
		}
		if (!desc.exists()) {
			desc.createNewFile();
		}
		return desc;
	}

	/**
	 * 编码文件名
	 */
	private static final String encodingFilename(String filename, String extension) {
		filename = filename.replace("_", " ");
		filename = new Md5Hash(filename + System.nanoTime() + counter++).toHex().toString() + extension;
		return filename;
	}

	/**
	 * 文件大小校验
	 *
	 * @param file
	 *            上传的文件
	 * @return
	 * @throws FileSizeLimitExceededException
	 *             如果超出最大大小
	 */
	public static final void assertAllowed(MultipartFile file) throws FileSizeLimitExceededException {
		long size = file.getSize();
		if (defaultMaxSize != -1 && size > defaultMaxSize) {
			throw new FileSizeLimitExceededException("not allowed upload upload", size, defaultMaxSize);
		}
	}

}
